Using the side fractions obtained from the GH extraction process of human pituitaries we are engaged in isolating B-lipotropin from Fraction 2 using combination of CMC chromatography, electrofocussing and preparative acrylamide gel electrophoresis. The material so obtained will be used for developing radioimmunoassay, as a source of B-endorphin, and for controlled studies of the effects of B-lipotropin on fat metabolism in man. In a separate study, bioassays for somatomedin are being used to study paradoxical GH regulatory responses in patients with long standing renal insufficiency and short-feed-back loop control of GH regulation in rats and man.